1. Field of the Invention
The present invention relates to a fuel injection device for injecting and supplying fuel toward an internal combustion engine from a fuel injection valve mounted at a throttle body, and more particularly, a structure of a fuel supply pipe in a multiple throttle body, in which a first fuel injection valve and a second injection valve are mounted at a single throttle body, and a plurality of such the throttle bodies arranged sideward.
2. Description of the Conventional Art
A conventional structure of a fuel supply pipe in a multiple throttle body comprising two injection valves is indicated in FIG. 6.
Reference numeral 30 is a throttle body in which an intake passage 31 is provided through and bored inside thereof. The intake passage 31 is opened and closed by a throttle valve 33 mounted at a throttle valve shaft 32, which crosses the intake passage 31 and is rotatably supported.
A first injection valve J1 and a second injection valve J2 are mounted at the throttle body 30. The first injection valve J1 is for injecting and supplying the fuel toward an intake passage 31a on the downstream side from the throttle valve 33, and the second injection valve J2 is for injecting and supplying the fuel toward an intake passage 31b on the upstream side from the throttle valve 33. Such the first fuel injection valve J1 shares a fuel supply area at the time of a low opening operation and an intermediate opening operation of the internal combustion engine. Such the second fuel injection valve J2 shares a fuel supply area at the time of a high opening operation of the internal combustion engine.
Further, when the multiple throttle body is formed, a plurality of single throttle bodies 30 comprising the two fuel injection valves J1, J2 are arranged sideward. At this time, each throttle body 30 is fixed by a mounting stay or the like with a desired mounting pitch, and the throttle valve shaft 32 in each throttle body 30 is linked to be simultaneously rotated.
As for the multiple throttle body illustrated in FIG. 6, four single throttle bodies 30 are fixed sideward.
Further, a first fuel distribution pipe 34 supporting a rear end portion of the first fuel injection valve J1 comprises four injection valve inserting holes (those are not illustrated in the drawings), a first fuel distribution passage 35 and a first fuel flow-in pipe 36. The four injection valve inserting holes are inserted with the rear end portions of respective first fuel injection valves J1, and are opened downwardly. The first fuel distribution passage 35 is for distributing and supplying the fuel toward each injection valve inserting hole, and is extended in the side direction. The first fuel flow-in pipe 36 is for introducing the fuel toward the first fuel distribution passage 35 from the outside.
Therefore, the first fuel distribution pipe 34 is fixedly provided sideward along the multiple throttle body, and the rear end portion of each first fuel injection valve J1 is inserted into each injection valve inserting hole, so that each first fuel injection valve J1 can be held by each throttle valve 30 and the first fuel distribution pipe 34.
On the other hand, a second fuel distribution pipe 37 supporting a rear end portion of the second fuel injection valve J2 comprises four injection valve inserting holes (those are not illustrated in the drawings), a second fuel distribution passage 38 and a second fuel flow-in pipe 39. The four injection valve inserting holes are inserted with the rear end portions of respective second fuel injection valves J2, and are opened downwardly. The second fuel distribution passage 38 is for distributing and supplying the fuel toward each injection valve inserting hole, and is extended in the side direction. The first fuel flow-in pipe 39 is for introducing the fuel toward the second fuel distribution passage 38 from the outside.
Therefore, the second fuel distribution pipe 37 is fixedly provided sideward along the multiple throttle body, and the rear end portion of each second fuel injection valve J2 is inserted into each injection valve inserting hole, so that each second fuel injection valve J2 can be held by each throttle valve 30 and the second fuel distribution pipe 37.